Few artists would consider cleaning the city streets, designing custom-built nuclear shelters or fighting charges of counterfeiting money as part of their activities. But then most artists don’t share the concerns that the members of Hi-Red Center (HRC) had as one of the most radical art groups to have emerged from postwar Japan.

Aspects of the short-lived group’s work have featured in exhibitions on Japanese postwar or avant-garde art; but until now there has been no in-depth exhibition dedicated to the group — a serious oversight considering their status in avant-garde art circles and their continuing influence, half a century later.

But now comes “Hi-Red Center: the Documents of ‘Direct Action’ ” at the Shoto Museum of Art in Tokyo’s Shibuya district. It’s the first exhibition devoted to cataloging and presenting as much of the group’s activities as possible — no easy task as the group issued no manifesto and largely eschewed leaving behind material artworks for posterity, in favor of articulating actions, gestures and events.

Already active and well known, Jiro Takamatsu, Genpei Akasegawa and Natsuyuki Nakanishi formed the group in Tokyo in 1963. The name Hi-Red Center was based on the meanings of the first kanji of each of their surnames — “taka” (high), “aka” (red) and “naka” (center). Nakanishi was associated with Japan’s neo-Dada movement and the other two had already begun a program of direct action, taking art and performance to the public.

This became something of an HRC strategy, with the artists seen quietly dragging a rope through a park or, in front of Shimbashi Station, attaching pins — a full decade before British punk — to one member’s hair, face and body.

One of the best-remembered actions by the group was actually its very last. “Street Cleaning Event” was held on a busy street in Ginza during the 1964 Tokyo Olympic Games, when the government was urging the country to present a clean image of the city. A group of half a dozen led by HRC core members were so earnest in their scrubbing and wiping that they were mistaken for being an official part of the government campaign they were taking a wry swipe at.

Operating under the cloak of officialdom was, in fact, another of their tactics — flyers they distributed to “announce” the event listed the name of organizations allegedly behind the cleaning campaign, half of them fake, half of them real entities. As ever, their motives remained elusive. The last thing they wanted to do was stage protests in the usual manner, preferring to raise questions rather than simple objections.

Going about their work quietly and methodologically, the suited and booted members conducted themselves more like businessmen than typical artists. For “Shelter Plan,” they pretended that a company had contracted them to make custom-designed nuclear shelters. Camped out in the Imperial Hotel, they invited friends and acquaintances to come in for fittings — photos show Yoko Ono, among others, getting measured up. Such acts, as documented in this exhibition, blur the lines between public space and gallery/museum, and between art, performance and everyday life.

“Hi-Red Center: the Documents of ‘Direct Action’ ” at the Shoto Museum of Art runs till March 23; open 10 a.m.- 6 p.m. (Fri. till 7 p.m.). ¥300. Closed Mon. www.shoto-museum.jp